This report comprises a study of splenic autotransplantation in omental pouches in rats. Twenty six rats were operated. The spleen (50%) was transplanted after splenectomy in four different fragments. The animals were re-explored after periods between 3 and 5 1/2 months and the splenic implants retrieved for histological examination as well as size and weight evolution. In 25/26 animals a viable spleen was identified. The mean weight of the retrieved spleen fragments was 150 mg versus 525 mg weight of the implanted materials. In no case there was an increase in size of the implanted fragments. Fifty-two of the 104 implanted fragments were retrieved with weight increase in 8.65% of them.